(function (doc, win) {
    // docEl html标签
    var docEl = doc.documentElement,


        resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
        recalc = function () {
            var clientWidth = docEl.clientWidth;
            if (!clientWidth) return;
            // html的fontsize = 换算比例 * (设备宽度 / 750)
            docEl.style.fontSize = 100 * (clientWidth / 750) + 'px';
            let a = docEl.style.fontSize = 100 * (clientWidth / 750) + 'px';
            // console.log(a);
            // console.log(docEl)
        };

    if (!doc.addEventListener) return;
    win.addEventListener(resizeEvt, recalc, false);
    doc.addEventListener('DOMContentLoaded', recalc, false);
})(document, window);
